Bloomberg has its own C++ standard library, BSL, which sits on top of another standard library but replaces containers with their own versions. The BSL containers are somewhat similar to Boost.Container's: they provide stateful allocators, as well as backport some C++11 extensions to C++03. Before I make all the necessary changes and do a pull request, I would like to make sure the Boost community would be ok in including support for this in Boost.Config. This library is fairly specific to one company and not used much elsewhere, despite being open-source (https://github.com/bloomberg/bde). We are also trying to phase out usage of this library with the 'std' namespace (it can be configured to use the 'bsl' namespace instead), but that's likely not going to happen anytime soon. As part as providing support for this in Boost, we would also be providing testers, mostly on big iron unix (AIX-powerpc, SunOS-sparc). Any interest?